Turbine-wheel and bucket.



No. 883,890. Q PATENTED APR. '7, 1908. W. KIESER.

TURBINE WHEEL AND BUCKET.

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- locking bucket.

UNITED STATES PATENT OFFICE.

WALTER K IESER, OF BERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A

CORPORATIONOF NEW YORK.

museum-mar. nun Boomer.

Specification of Letters Patent. Application filed mm 15, 1906. Serial na aasaa Patented April 7, 190

To all whom it may concern:

Be it known that I, WALTER KIEsEa, a citizen of Switzerland, residing at Berlin, Germany, have invented certam new and useful Im rovements in Turbine- Wheels and Buckets herefor, ofwhich the following is a specification.

The present invention relates to the construction of turbine wheels and buckets therefor, and has for its object to provide a bucket wheel of improved construction which is especially adapted for high bucket speeds.

In the accompanying drawing which illustrates one of the embodiments of my inven tion, Fi e 1 is a artial view in elevation ig. 2 is an axial section is an axial section of the wheel showing the arrangement whereby-the buckets can be inserted in the retaining groove in the wheel rim; and Fig. 5 is a perspective view ofa 1 represents the web of the wheel having a I rim 2, the latter containing a groove 3 to receive the bases 4 of the buckets 5. The buckets may be of any suitable shape in cross-section, those shown bein substantially crescent-shaped. Each buc et is provided with a base, the latter having an extension or shank 6 of such construction that it will engage the walls of the groove in the support and hold the bucket in place. The

shank can be made in a variety of ways and of various shapes. For high bucket s eeds the inverted T form shown has been ound to be most satisfactory. The centrifugal force due to the rotation of high-speed buckets is very great and in choosing the form of the shank it is important that when the wheel is rotating there shall be no horizontal component tending to spread the wallsof the groove in the wheel or other sup ort.

In the construction shown eac bucket is independent of every other bucket and the base therefor is made by casting molten metal around the end of the bucket. The

base will usually be finished somewhat before being mounted in place. -All the buckets are I alike except the one or more locking buckstrains on the lOCklIlf has no I provided which enter the groove 3 and extend through the side of the rim of the wheel.

.Each recess is of such a size and shape that the shanks of the buckets can readily be inserted, and from it into the groove. In Fi 5 is shown one of-the locking buckets; It 1s provided with a shoulder 8 adapted to engage with the shoulder-9 formed on the rim .of the wheel. It is also provided with op ositely extending ribs or projections 10 an 11 which enter recesses formed in the sides of the main recess 7 and engage suitable shoulders. These ribs or projections are made stron since they take a large part of the centrifug bucket. The total strain is therefore divi ed between these projeotions and the shoulder 8. It will thus be seen that the locking piece has a three point bearing, one at the front and the other 'twoon the sides. The bucket extends upward from the base and at its upper end 1s provided with one or more tenons 12. In the case of relatively thin and wide buckets intended for very high bucket s eeds it is desirable-Ito provide two tenons w ich enter correspondingly shaped holes in the cover and secure the latter in The locking bucket, asbefore stated, is constructed so as to withstand the high centrifugal strains to which it is subjected, and there is no tendency for it to work out axially owing to the factthat the strains are perpendlcular to the axis. the locking bucket from working out from any cause whatsoever a screw 13 is provided which is threaded into therim and also into thebase' of the bucket. After the screw is seated the metal surrounding the head can be upset to revent the screw from backing out. In making the wheel the web and rim are machined in the usual way after which the groove 3 is turned. The side opening recess 7 of which one or-more may be provided are then made.

It is to be observed that the fastening means for the lockin bucket are situated below the peripheral f ace of the wheel where place by being riveted over.

In order to prevent they are out of the way, and are of such a character that they will not be injured in case the buckets rub on a stationary part of the machine. It is also to be noted that the screw 13 merely serves to prevent the locking bucket from -moving axially and therefore rt in resisting the centrifugalstrains to whic i the bucket is subjected. V

Wltll the a paratus which I now consider to re resent t e best embodiment thereof but -I esire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A turbine wheel having a rim with an inverted T-sha ed groove and a filling recess opening latera y through the side of the rim, a plurality of buckets having bases fitted into the roove, a locking piece, axially extending oulders between the locking piece and the rim which are situated below the peripheral face of the rim [or restraining the said iiece against centrifugal strains, and a means for preventing the locking piece from moving axially.

I 2. A turbine wheel having a rim with a groove therein and a side 0 ening recess, a lurality of buckets mounte in the roove, a

ibcking piece carr ing a bucket and fillin the recess, and shou ders between the locking piece and the walls of the recess and located above the bottom of the roove to hold said piece against centrifugal, force.

3. A turbine Wheel having a rim with a groove therein and a side 0 ening recess, a luralit'y of buckets mounte 1n the groove, a

OCking piece carrying a bucket and filling the recess, shoulders between the locking piece and the walls of the recess to hold sai piece against "centrifugal force, and a screw which is threaded into the, rim and said piece to prevent the latter from working axie ally out of the recess.

4. A turbine wheel having a bucket supporting portion which is provided with a groovehaving under cut walls and a side opening recess, buckets the bases of which are mounted in the said groove and retained by the walls thereof, and a locking piece which fills said recess and is supported by a threeoint bearing.

' 5. d turbine wheel having a bucket supporting portion which is-provided with an mverted T-shaped groove and a side 0 ening fillingrecess, buckets having T-shape bases fitted into the groove, a locking piece having a rojection on the front whic' engages a wal of the bucket retaining groove, and means between the side of the locking .piece and the walls of the said recess cooperating with the projection to hold said locking piece against centrifugal force.

6. An individual bucket for a turbine comprising a single body portion having a tenon tormed on one end and a base cast around the other, the said base being provided with shoulders adapted to engage in a support for holding the bucket.

In witness whereof, I have hereunto set n my hand this sixth day of Oct. 1906.

' WALTER KIESER.

Witnesses:

ALEX. F. MACDONALD, HELEN ORFORD. 

